Fig. 1

Model schematic: interaction between CSF and cardiovascular systems in upright posture. In the mathematical model, CSF and venous blood are divided into cranial and spinal compartments. The corresponding pressures at the cranial (\(p_{CSF}^{c}\) and \(p_{v}^{c}\)) and spinal (\(p_{CSF}^{c}\) and \(p_{v}^{c}\)) level differ by hydrostatic pressure columns that are characterized by the distances \(l_{sc}\) and \(l_{jug}\). The interaction of CSF and venous blood is determined by the local pressure–volume relationships (\(\Delta V^{c}\) and \(\Delta V^{s}\)). The pulsating arterial blood flow \(Q_{a}\) leads to a pulsating change in the cranial arterial blood volume \(\Delta V_{a}\), which is compensated by craniospinal flows of CSF and venous blood (\(Q_{CSF}\) and \(Q_{v}\)). CSF formation (\(Q_{form}\)) and absorption (\(Q_{abs}\)) are also indicated